Moonship Photographed by Backyard Astronomers

July
9, 2009: On June 29th, neighbors of Paul Mortfield
in Ontario, Canada, heard "cheers of excitement"
coming from the astronomer's house. What caused the commotion?

"I
had just observed NASA's LCROSS spacecraft," explains
Mortfield. Using no more than a backyard telescope, he caught
it zipping past spiral galaxy IC3808:

Above:
LCROSS photographed on June 29, 2009, by Paul Mortfield using
a remotely-operated 16-inch telescope. The spacecraft was
about 480,000 km from Earth.

LCROSS
is the Lunar Crater Observation and Sensing Satellite. It
left Earth June 18th atop an Atlas V rocket on a mission to
crash into the Moon. On Oct. 9th, NASA plans to plunge LCROSS
headfirst into a deep crater near the Moon's south pole. Researchers
hope the debris it kicks up will reveal water and other minerals
of use to future lunar explorers.

Meanwhile,
LCROSS is circling the Earth-moon system in a long looping
orbit, and NASA is inviting amateur astronomers to help track
it.

"The
more eyes the better," says Brian Day of NASA's Ames Research
Center. "We've got to crash this spacecraft into the bottom
of a pitch-black crater a quarter of a million miles away with
pinpoint accuracy. Amateur astronomers [can help us] precisely
determine the position of LCROSS in flight."

Typically,
LCROSS is in contact with the busy Deep Space Network once
every three days, which meets all mission requirements. Amateurs
can fill in the gaps by observing LCROSS every day.

"During
flight, you want to have as many eyes as possible on your
spacecraft," notes Day, "not only for tracking,
but also in case there is an anomaly. In the past, amateurs
have been able to capture venting of materials from shuttles
and other spacecraft."

Paul
Mortfield had little trouble pinpointing LCROSS: "I was
quite surprised at how easy it was to find and follow using
my 16-inch telescope. I didn't know what brightness to expect
or even if it would be where the ephemeris predictedâbut there
it was. I saw it in my first 60 second exposure."

"There
were definitely cheers of excitement around the house when
I saw it on the computer screen."

Mortfield
estimates the brightness of the spacecraft to be 16th magnitude,
similar to that of many near-Earth asteroids. To find it,
he recommends pointing your web browser at JPL's online Horizons
ephemeris system (link)
and entering 'LCROSS' as the target body. The program will
generate a set of coordinates you can plug into the tracking
system of almost any modern backyard telescope.

Since
Mortfield first caught sight of LCROSS on June 29th, others
have seen it too. Portuguese amateur Paulo Lobao photographed
LCROSS using a refracting telescope only 4-inches in diameter:
details.

Indeed,
says Day, LCROSS is a fairly easy target for experienced amateurs,
and he'd love nothing better than to recruit hundreds of observers
to keep track of LCROSS in the months ahead. How does an astronomer
get started? "Go to the LCROSS observer's group (link).
Start reading the articles and chatting with other observers,"
he suggests.

The
really big event comes in October when LCROSS crashes into
the Moon. Amateur astronomers will be able to observe that,
too. Stay tuned for impact observing tips, coming soon from
Science@NASA.